Superior Court Judge Howard Simms threw out crime-lab blood tests and some police questioning that prosecutors want to use in the murder trial of Stephen McDaniel.
At a hearing on defense motions Thursday, a prosecutor said "we do not know what happened" to cause the death of Lauren Giddings.
The judge threw out questioning of McDaniel made in the hours after Giddings' body was found in a trash bin near their Macon apartment complex on June 30, 2011.
McDaniel and Giddings were neighbors and Mercer Law School classmates.
The judge agreed with defense attorney Franklin Hogue that McDaniel was effectively in custody during the questioning but was not read his Miranda rights to remain silent until the next morning, when he was charged with unrelated burglaries in the apartment complex. He was charged with murder a month later.
The defense played several minutes of video of the police interrogation.
Simms said police statements to McDaniel made clear he was already in custody. One such statement was that his family "is going to come here and cry and kiss you goodbye".
On the excerpt of the video, McDaniel says "I didn't do anything."
The judge also threw out evidence involving the police use of Luminol, a substance used to detect blood. The defense says the Luminol tests done in Giddings' bathroom are only "presumptive."
Thursday, police Sgt. Steve Gatlin testified that investigators saw blood in Giddings' bathtub and took swabs of it. Gatlin worked in the Macon police crime lab at the time.
But Gatlin said crime-lab testing using Luminol did not find any blood in Giddings' bathroom. Hogue said FBI testing confirmed that Giddings' blood was not on the swabs.
Under cross-examination by Assistant District Attorney Nancy Scott Malcor, Gatlin said Luminol can register positive for other substances including fecal matter, metals and cleaning supplies. He said Luminol registered a strong response when applied to Giddings' bathtub and did not when applied in two other bathrooms that day.
Scott Malcor argued that Luminol evidence remained relevant because it registered strongly in Giddings' bathtub and "may very well have reacted with cleaning supplies."
Judge Simms said that argument at trial would create an unfair inference that McDaniel cleaned up after a murder.
Simms set January 6 for a court hearing concerning another blog post uncovered by prosecutors that they link to McDaniel.
Under the name "Sons of Liberty," the writer described using a knife on the neck of a victim to cut the carotid artery. The entry was posted in 2008.
The judge said GBI and FBI investigators will be called to testify about the blog post and its authorship.
The judge denied several defense motions challenging searches of McDaniel's apartment.
Among them, the judge rejected a defense challenge to the seizure of keys from McDaniel's apartment -- one for Giddings' apartment next door, the other a master key for the apartment complex. While the judge said the seizure was outside the scope of a search warrant, the keys would have eventually been found as police investigated how McDaniel got into Giddings' apartment after her disappearance.
The judge allowed the introduction at trial of swords, knives and large sticks found in McDaniel's apartment, but not three guns or a baseball bat.
The prosecution argued that all of those objects were relevant because "we do not know what happened to cause her death." Giddings' head has not been found.
The judge said any inference that McDaniel committed a murder because he owned a gun or a baseball bat would be unfair. He allowed what he called the "edge weapons" -- swords and knives.
The judge denied a motion to exclude DNA evidence taken from a bloodied hacksaw. Investigators found it in a storage closet at the apartment complex.
Hogue, the defense attorney, said the hacksaw could be evidence of a dismemberment but not a murder. He added, "There's 10,000 ways to kill a person."
Judge Simms joked, "I think I saw that show."